T-MOBILE USA, INC.
14 prefixes in 307 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 307-203 | JACKSON | 6529 | 2001-03-14 | Yes |
| 307-220 | CHEYENNE | 6529 | — | Yes |
| 307-221 | CHEYENNE | 6529 | — | Yes |
| 307-355 | LA GRANGE | 6529 | 2020-07-29 | Yes |
| 307-385 | JACKSON | 6529 | 2025-11-06 | Yes |
| 307-394 | CASPER | 6529 | 2021-05-21 | Yes |
| 307-410 | POWELL | 6529 | 2022-03-22 | Yes |
| 307-419 | CODY | 6529 | 2022-03-24 | Yes |
| 307-428 | DOUGLAS | 6529 | 2023-12-01 | Yes |
| 307-435 | SHERIDAN | 6529 | 2025-12-03 | Yes |
| 307-478 | LA GRANGE | 6529 | 2025-02-05 | Yes |
| 307-482 | WHEATLAND | 6529 | 2025-04-08 | Yes |
| 307-485 | CASPER | 6529 | 2025-05-06 | Yes |
| 307-920 | CHEYENNE | 6529 | — | Yes |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.